Vicious cycle of vitamin B1 insufficiency and heart failure in cardiology outpatients.

Heart failure is a major manifestation of vitamin B₁ deficiency; beriberi. We have previously reported that even vitamin B₁ insufficiency, milder than deficiency, is a risk for heart failure in the institutionalized elderly. Then in this cross-sectional study, sixty-eight cardiology outpatients were evaluated for their whole blood vitamin B₁ and plasma brain natriuretic peptide (BNP) concentrations, a sensitive marker of heart failure, as well as their dietary intake. Whole blood vitamin B₁ concentration was significantly correlated with plasma BNP level in vitamin B₁-deficient/insufficient patients (whole blood vitamin B₁<28 ‍ng/ml) but not in sufficient patients. Whole blood vitamin B₁ concentration was significantly lower in loop diuretics users than non-users. Multiple regression analysis has identified whole blood vitamin B₁ concentration and eGFR as the significant contributors to log-transformed plasm BNP level, and loop diuretics use, serum albumin level, and eGFR as the contributors to whole blood vitamin B₁ concentration. ROC analysis has shown the significant predictability of whole blood vitamin B₁ for plasma BNP ≥100 pg/ml with the cut-off value of 23.5 ‍ng/ml. Vitamin B₁ insufficiency is a risk of heart failure in the cardiology outpatients, and the therapeutic use of loop diuretics aggravates heart failure and possibly forms a vicious cycle.